Find the measurement of the arc or central angle indicated?!

Adiverr from the university of florida women’s swimming and diving team is competing in the ncaa zone b championships

The perimeter of a rectangle is 42 inches. if the width of the rectangle is 6 inches, what is the length

What is the next step in the given proof? choose the most logical approach. a. statement: m 1 + m 2 + 2(m 3) = 180° reason: angle addition b. statement: m 1 + m 3 = m 2 + m 3 reason: transitive property of equality c. statement: m 1 = m 2 reason: subtraction property of equality d. statement: m 1 + m 2 = m 2 + m 3 reason: substitution property of equality e. statement: 2(m 1) = m 2 + m 3 reason: substitution property of equality